A synthetic peptide having nestin expression inducing ability which allows induction of expression of nestin in astrocytes; an agent for inducing nestin expression including the peptide as an active ingredient; and a method for producing high nestin expressing cells derived from astrocytes, the method being characterized in that the agent for inducing nestin expression is supplied. The agent for inducing nestin expression provided by the present invention includes, as an active ingredient, a synthetic peptide including a nestin-inducing peptide sequence consisting of an amino acid sequence of SEQ ID NO: 1 or an amino acid sequence formed by conservative replacement of 1, 2 or 3 amino acid residues in the amino acid sequence. The method for producing high nestin expressing cells derived from astrocytes provided by the present invention includes preparing an astrocyte culture, and supplying, at least once, the agent for inducing nestin expression to the astrocyte culture.